let hd = "hdddddd";
console.log(hd.match(/hd+/));
console.log(hd.match(/hd+?/));
console.log(hd.match(/hd*?/));
console.log(hd.match(/hd{2,}?/));
//?表示0|1贪婪的有就是1个
console.log(hd.match(/hd?/));
console.log(hd.match(/hd??/));
